A retrospective cohort study of a community-based primary care program’s effects on pharmacotherapy quality in low-income Peruvians with type 2 diabetes and hypertension

Little is known about the effects of the Chronic Care Model (CCM) and community health workers (CHWs) on pharmacotherapy of type 2 diabetes and hypertension in resource-poor settings. This retrospective cohort implementation study evaluated the effects of a community-based program consisting of CCM, CHWs, guidelines-based treatment protocols, and inexpensive freely accessible medications on type 2 diabetes and hypertension pharmacotherapy quality. A door-to-door household survey identified 856 adults 35 years of age and older living in a low-income Peruvian community, of whom 83% participated in screening for diabetes and hypertension. Patients with confirmed type 2 diabetes and/or hypertension participated in the program’s weekly to monthly visits for < = 27 months. The program was implemented as two care periods employed sequentially. During home care, CHWs made weekly home visits and a physician made treatment decisions remotely. During subsequent clinic care, a physician attended patients in a centralized clinic. The study compared the effects of program (pre- versus post-) (N = 262 observations), and home versus clinic care periods (N = 211 observations) on standards of treatment with hypoglycemic and antihypertensive agents, angiotensin converting enzyme inhibitors, and low-dose aspirin. During the program, 80% and 50% achieved hypoglycemic and antihypertensive standards, respectively, compared to 35% and 8% prior to the program, RRs 2.29 (1.72–3.04, p <0.001) and 6.64 (3.17–13.9, p<0.001). Achievement of treatment standards was not improved by clinic compared to home care (RRs 1.0 +/- 0.08). In both care periods, longer retention in care (>50% of allowable time) was associated with achievement of all treatment standards. 85% compared to 56% achieved the hypoglycemic treatment standard with longer and shorter retention, respectively, RR 1.52 (1.13–2.06, p<0.001); 56% compared to 27% achieved the antihypertensive standard, RR 2.11 (1.29–3.45, p<0.001). In a dose-dependent manner, the community-based program was associated with improved guidelines-based pharmacotherapy of type 2 diabetes and hypertension.

The primary care program is based on a logic model with inter-related processes, each associated with clinical outcomes (Figure 1 and Table 1), and the effect of interventions (the Chronic Care Model (CCM), community health workers (CHWs), and reduced out-of-pocket (OOP) costs) on these processes and outcomes (Figure 2 and Table 2).The program specifically targets the process triad of retention in care, OOP costs, and treatment intensification.(A) Retention in care, e.g., shorter visit intervals (9, 10) and continuity of care (10,11), has positive effects on treatment intensification (9, 10) and mitigates treatment inertia (12).(B) Out-of-pocket medication costs are associated with treatment inertia (13,14).(C) Out-of-pocket medication costs are associated with poor retention in care (13)(14)(15), (D) Out-of-pocket medication costs are associated with poor medication adherence (16)(17)(18)(19).

Figure 1 .
Figure 1.Inter-related care processes and clinical outcomes of type 2 diabetes and hypertension

Figure 2 and
Figure 2 and Table2shows CCM, CHW, and reduced OOP cost interventions (the three elements of the Siempre Salud primary care program for chronic diseases) and their effects on processes and outcomes.

Figure 2 .
Figure 2. Intervention associations with improved processes and clinical outcomes

Table 1 .
Process associations with clinical outcomes of type 2 diabetes and hypertension DM = type 2 diabetes, HTN = hypertension

Table 2 .
Interventions associated with improved processes and clinical outcomes